The downregulation of Lcn2 expression by vitamin D supplementation in vivo as indicated by microarray were confirmed by RT-qPCR (Fig. 3c) and IHC staining (Fig. 3d and 3e), which showed that both of Lcn2 mRNA and protein expressions were significantly reduced in ICC tumors from +6D group compared to those from -D group. This evidence concerns the gene LCN2 and intrahepatic cholangiocarcinoma.